Merge commit 'origin/master' into on-waves/bsc-master

Conflicts:
	openbsc/include/openbsc/Makefile.am
	openbsc/include/openbsc/gsm_data.h
	openbsc/src/Makefile.am
	openbsc/src/abis_rsl.c
	openbsc/src/chan_alloc.c
	openbsc/src/gsm_04_08.c
	openbsc/src/gsm_data.c
	openbsc/src/vty_interface.c

The biggest problem is the moving of the RTP code into
the RSL layer. This may break quite some things...

1 files changed, 367 insertions, 0 deletions

diff --git a/openbsc/src/handover_logic.c b/openbsc/src/handover_logic.c
new file mode 100644
index 000000000..d40374f10
--- /dev/null
+++ b/openbsc/src/handover_logic.c
@@ -0,0 +1,367 @@
+/* Handover Logic for Inter-BTS (Intra-BSC) Handover.  This does not
+ * actually implement the handover algorithm/decision, but executes a
+ * handover decision */
+
+/* (C) 2009 by Harald Welte <laforge@gnumonks.org>
+ *
+ * All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <time.h>
+#include <netinet/in.h>
+
+#include <openbsc/msgb.h>
+#include <openbsc/debug.h>
+#include <openbsc/gsm_data.h>
+#include <openbsc/gsm_utils.h>
+#include <openbsc/gsm_subscriber.h>
+#include <openbsc/gsm_04_08.h>
+#include <openbsc/abis_rsl.h>
+#include <openbsc/chan_alloc.h>
+#include <openbsc/signal.h>
+#include <openbsc/talloc.h>
+#include <openbsc/transaction.h>
+#include <openbsc/rtp_proxy.h>
+
+struct bsc_handover {
+	struct llist_head list;
+
+	struct gsm_lchan *old_lchan;
+	struct gsm_lchan *new_lchan;
+
+	struct timer_list T3103;
+
+	u_int8_t ho_ref;
+};
+
+static LLIST_HEAD(bsc_handovers);
+
+static struct bsc_handover *bsc_ho_by_new_lchan(struct gsm_lchan *new_lchan)
+{
+	struct bsc_handover *ho;
+
+	llist_for_each_entry(ho, &bsc_handovers, list) {
+		if (ho->new_lchan == new_lchan)
+			return ho;
+	}
+
+	return NULL;
+}
+
+static struct bsc_handover *bsc_ho_by_old_lchan(struct gsm_lchan *old_lchan)
+{
+	struct bsc_handover *ho;
+
+	llist_for_each_entry(ho, &bsc_handovers, list) {
+		if (ho->old_lchan == old_lchan)
+			return ho;
+	}
+
+	return NULL;
+}
+
+/* Hand over the specified logical channel to the specified new BTS.
+ * This is the main entry point for the actual handover algorithm,
+ * after it has decided it wants to initiate HO to a specific BTS */
+int bsc_handover_start(struct gsm_lchan *old_lchan, struct gsm_bts *bts)
+{
+	struct gsm_lchan *new_lchan;
+	struct bsc_handover *ho;
+	static u_int8_t ho_ref;
+	int rc;
+
+	/* don't attempt multiple handovers for the same lchan at
+	 * the same time */
+	if (bsc_ho_by_old_lchan(old_lchan))
+		return -EBUSY;
+
+	DEBUGP(DHO, "(old_lchan on BTS %u, new BTS %u)\n",
+		old_lchan->ts->trx->bts->nr, bts->nr);
+
+	bts->network->stats.handover.attempted++;
+
+	new_lchan = lchan_alloc(bts, old_lchan->type);
+	if (!new_lchan) {
+		LOGP(DHO, LOGL_NOTICE, "No free channel\n");
+		bts->network->stats.handover.no_channel++;
+		return -ENOSPC;
+	}
+
+	ho = talloc_zero(NULL, struct bsc_handover);
+	if (!ho) {
+		LOGP(DHO, LOGL_FATAL, "Out of Memory\n");
+		lchan_free(new_lchan);
+		return -ENOMEM;
+	}
+	ho->old_lchan = old_lchan;
+	ho->new_lchan = new_lchan;
+	ho->ho_ref = ho_ref++;
+
+	/* copy some parameters from old lchan */
+	memcpy(&new_lchan->encr, &old_lchan->encr, sizeof(new_lchan->encr));
+	new_lchan->ms_power = old_lchan->ms_power;
+	new_lchan->bs_power = old_lchan->bs_power;
+	new_lchan->rsl_cmode = old_lchan->rsl_cmode;
+	new_lchan->tch_mode = old_lchan->tch_mode;
+	new_lchan->subscr = subscr_get(old_lchan->subscr);
+
+	/* FIXME: do we have a better idea of the timing advance? */
+	rc = rsl_chan_activate_lchan(new_lchan, RSL_ACT_INTER_ASYNC, 0,
+				     ho->ho_ref);
+	if (rc < 0) {
+		LOGP(DHO, LOGL_ERROR, "could not activate channel\n");
+		talloc_free(ho);
+		lchan_free(new_lchan);
+		return rc;
+	}
+
+	llist_add(&ho->list, &bsc_handovers);
+	/* we continue in the SS_LCHAN handler / ho_chan_activ_ack */
+
+	return 0;
+}
+
+/* T3103 expired: Handover has failed without HO COMPLETE or HO FAIL */
+static void ho_T3103_cb(void *_ho)
+{
+	struct bsc_handover *ho = _ho;
+
+	DEBUGP(DHO, "HO T3103 expired\n");
+	ho->new_lchan->ts->trx->bts->network->stats.handover.timeout++;
+
+	lchan_free(ho->new_lchan);
+	llist_del(&ho->list);
+	talloc_free(ho);
+}
+
+/* RSL has acknowledged activation of the new lchan */
+static int ho_chan_activ_ack(struct gsm_lchan *new_lchan)
+{
+	struct bsc_handover *ho;
+	int rc;
+
+	/* we need to check if this channel activation is related to
+	 * a handover at all (and if, which particular handover) */
+	ho = bsc_ho_by_new_lchan(new_lchan);
+	if (!ho)
+		return -ENODEV;
+
+	DEBUGP(DHO, "handover activate ack, send HO Command\n");
+
+	/* we can now send the 04.08 HANDOVER COMMAND to the MS
+	 * using the old lchan */
+
+	rc = gsm48_send_ho_cmd(ho->old_lchan, new_lchan, 0, ho->ho_ref);
+
+	/* start T3103.  We can continue either with T3103 expiration,
+	 * 04.08 HANDOVER COMPLETE or 04.08 HANDOVER FAIL */
+	ho->T3103.cb = ho_T3103_cb;
+	ho->T3103.data = ho;
+	bsc_schedule_timer(&ho->T3103, 10, 0);
+
+	/* create a RTP connection */
+	if (is_ipaccess_bts(new_lchan->ts->trx->bts))
+		rsl_ipacc_crcx(new_lchan);
+
+	return 0;
+}
+
+/* RSL has not acknowledged activation of the new lchan */
+static int ho_chan_activ_nack(struct gsm_lchan *new_lchan)
+{
+	struct bsc_handover *ho;
+
+	ho = bsc_ho_by_new_lchan(new_lchan);
+	if (!ho) {
+		LOGP(DHO, LOGL_ERROR, "unable to find HO record\n");
+		return -ENODEV;
+	}
+
+	llist_del(&ho->list);
+	talloc_free(ho);
+
+	/* FIXME: maybe we should try to allocate a new LCHAN here? */
+
+	return 0;
+}
+
+/* GSM 04.08 HANDOVER COMPLETE has been received on new channel */
+static int ho_gsm48_ho_compl(struct gsm_lchan *new_lchan)
+{
+	struct bsc_handover *ho;
+
+	ho = bsc_ho_by_new_lchan(new_lchan);
+	if (!ho) {
+		LOGP(DHO, LOGL_ERROR, "unable to find HO record\n");
+		return -ENODEV;
+	}
+
+	new_lchan->ts->trx->bts->network->stats.handover.completed++;
+
+	bsc_del_timer(&ho->T3103);
+
+	/* update lchan pointer of transaction */
+	trans_lchan_change(ho->old_lchan, new_lchan);
+
+	ho->old_lchan->state = LCHAN_S_INACTIVE;
+
+	/* do something to re-route the actual speech frames ! */
+
+	llist_del(&ho->list);
+	talloc_free(ho);
+
+	return 0;
+}
+
+/* GSM 04.08 HANDOVER FAIL has been received */
+static int ho_gsm48_ho_fail(struct gsm_lchan *old_lchan)
+{
+	struct bsc_handover *ho;
+
+	ho = bsc_ho_by_old_lchan(old_lchan);
+	if (!ho) {
+		LOGP(DHO, LOGL_ERROR, "unable to find HO record\n");
+		return -ENODEV;
+	}
+
+	old_lchan->ts->trx->bts->network->stats.handover.failed++;
+
+	bsc_del_timer(&ho->T3103);
+	llist_del(&ho->list);
+	put_lchan(ho->new_lchan);
+	talloc_free(ho);
+
+	return 0;
+}
+
+/* GSM 08.58 HANDOVER DETECT has been received */
+static int ho_rsl_detect(struct gsm_lchan *new_lchan)
+{
+	struct bsc_handover *ho;
+
+	ho = bsc_ho_by_new_lchan(new_lchan);
+	if (!ho) {
+		LOGP(DHO, LOGL_ERROR, "unable to find HO record\n");
+		return -ENODEV;
+	}
+
+	/* FIXME: do we actually want to do something here ? */
+
+	return 0;
+}
+
+static int ho_ipac_crcx_ack(struct gsm_lchan *new_lchan)
+{
+	struct bsc_handover *ho;
+	struct rtp_socket *old_rs, *new_rs, *other_rs;
+
+	ho = bsc_ho_by_new_lchan(new_lchan);
+	if (!ho) {
+		LOGP(DHO, LOGL_ERROR, "unable to find HO record\n");
+		return -ENODEV;
+	}
+
+	if (ipacc_rtp_direct) {
+		LOGP(DHO, LOGL_ERROR, "unable to handover in direct RTP mode\n");
+		return 0;
+	}
+
+	/* RTP Proxy mode */
+	new_rs = new_lchan->abis_ip.rtp_socket;
+	old_rs = ho->old_lchan->abis_ip.rtp_socket;
+
+	if (!new_rs) {
+		LOGP(DHO, LOGL_ERROR, "no RTP socket for new_lchan\n");
+		return -EIO;
+	}
+
+	rsl_ipacc_mdcx_to_rtpsock(new_lchan);
+
+	if (!old_rs) {
+		LOGP(DHO, LOGL_ERROR, "no RTP socekt for old_lchan\n");
+		return -EIO;
+	}
+
+	/* copy rx_action and reference to other sock */
+	new_rs->rx_action = old_rs->rx_action;
+	new_rs->tx_action = old_rs->tx_action;
+	new_rs->transmit = old_rs->transmit;
+
+	switch (ho->old_lchan->abis_ip.rtp_socket->rx_action) {
+	case RTP_PROXY:
+		other_rs = old_rs->proxy.other_sock;
+		rtp_socket_proxy(new_rs, other_rs);
+		/* delete reference to other end socket to prevent
+		 * rtp_socket_free() from removing the inverse reference */
+		old_rs->proxy.other_sock = NULL;
+		break;
+	case RTP_RECV_UPSTREAM:
+		new_rs->receive = old_rs->receive;
+		break;
+	case RTP_NONE:
+		break;
+	}
+
+	return 0;
+}
+
+static int ho_logic_sig_cb(unsigned int subsys, unsigned int signal,
+			   void *handler_data, void *signal_data)
+{
+	struct gsm_lchan *lchan;
+
+	switch (subsys) {
+	case SS_LCHAN:
+		lchan = signal_data;
+		switch (signal) {
+		case S_LCHAN_ACTIVATE_ACK:
+			return ho_chan_activ_ack(lchan);
+		case S_LCHAN_ACTIVATE_NACK:
+			return ho_chan_activ_nack(lchan);
+		case S_LCHAN_HANDOVER_DETECT:
+			return ho_rsl_detect(lchan);
+		case S_LCHAN_HANDOVER_COMPL:
+			return ho_gsm48_ho_compl(lchan);
+		case S_LCHAN_HANDOVER_FAIL:
+			return ho_gsm48_ho_fail(lchan);
+		}
+		break;
+	case SS_ABISIP:
+		lchan = signal_data;
+		switch (signal) {
+		case S_ABISIP_CRCX_ACK:
+			return ho_ipac_crcx_ack(lchan);
+			break;
+		}
+		break;
+	default:
+		break;
+	}
+
+	return 0;
+}
+
+static __attribute__((constructor)) void on_dso_load_ho_logic(void)
+{
+	register_signal_handler(SS_LCHAN, ho_logic_sig_cb, NULL);
+	register_signal_handler(SS_ABISIP, ho_logic_sig_cb, NULL);
+}